Fitting device for the accessories of a camera

ABSTRACT

Fitting device for the accessories such as lens hood, etc. by means of a revolving bayonet mount system, comprising projections for fitting on the periphery of lens tube, the accessories having brims engageable with said projections and elastic pieces made of synthetic material, and at an engaged position of said projections with said brims, said elastic pieces are compressed between said projections of the lens tube and the accessories, thus the latter is held on the former by the resiliency of said elastic pieces.

United States Patent [191 Kanie et al.

[ 1 Sept. 11, 1973 FITTING DEVICE FOR THE ACCESSORIES OF A CAMERA [75]Inventors: Shiomi Kanie, Midori-ku, Higashi I-Iongo Daini Jutaku,Yohohama; Takeo Shoji, Meguro-ku, Tokyo; Isao Nogi, Kanagawa-ku,Yokohama; Taizo Mitani, Kohuku-ku, Yokohama, all of Japan [73] Assignee:Canon Kabushiki Kaisha, Tokyo,

' Japan [22] Filed: Apr. 4, 1972 [21] Appl. No.: 241,034

[30] Foreign Application Priority Data Apr. 16, 1971 Japan 46/2478] [52]US. Cl. 350/257, 350/251 [51] Int. Cl.. G02b 7/02 [58] Field of Search..350/245257, 178

[56] References Cited UNITED STATES PATENTS 3,572,905 3/1971 Schlapp350/257 3,441,339 4/1969 Rederer et al. 350/255 FOREIGN PATENTS ORAPPLICATIONS 621,875 4/1949 Great Britain 350/252 Primary ExaminerDavidSchonberg Assistant Examiner-Michael J. Tokar Attorney-John J. McGlew etal.

[57] ABSTRACT Fitting device for the accessories such as lens hood, etc.by means of a revolving bayonet mount system, comprising projections forfitting on the periphery of l\.l1S tube, the accessories having brimsengageable with said projections and elastic pieces made of syntheticmate rial, and at an engaged position of said projections with saidbrims, said elastic pieces are compressed between said projections ofthe lens tube and the accessories, thus the latter is held on the formerby the resiliency of said elastic pieces.

8 Claims, 6 Drawing Figures FITTING DEVICE FOR THE ACCESSORIES OF ACAMERA BACKGROUND OF INVENTION Usually, in these kinds of bayonet mountsystem, there are well known those devices, in which joining projectionsor overlapped portions of brims are pressed by metallic springs, thusholding the accessories on the camera body or the lens tube by thefrictional force, however, in such devices, there are disadvantages thatwhen the accessories are attached and detached, the surface of joiningprojections is injured or its coating is peeled away by the frictionwith the spring or the joining projections cooperating therewith,resulting in the injury of its external appearance.

It is the object of this invention to eliminate said disadvantages ofthe fitting device in such a manner that instead of said metallicsprings, holding pieces made of elastic material are used to holdaccessories such as lens hood by their pressure in radial direction.

SUMMARY OF INVENTION This invention relates to a fitting device for theaccessories of a camera, more particularly to an improvement of a devicefor fitting the accessories such as lens hood onto the front end of alens tube by means of the bayonet mount system.

According to this invention, the fitting device is formed in combinationof constructive elements, comprising a lens tube for camera havingplural joining projections, accessories for a camera having fittingportions to said lens tube and having plural brims engageable with saidjoining projections on said fitting portions, wherein said accessoriesare locked in such a manner that the brims thereof will engage with thejoining projections at a position revolved from the fitting position tothe lens tube in a certain angle, thus preventing the accessories fromslipping out forward. The fitting portions of said accessories to saidlens tube have holding pieces made of elastic material and these piecesare compressed between the projections of said lens tube and theaccessories at said locked position, thus the accessories are held onthe lens tube by the resiliency of said elastic pieces.

BRIEF DESCRIPTION OF DRAWINGS In the accompanying drawings, someembodiments of this invention are shown in schematic manner, in which;

FIG. 1 is a perspective view of disassembled fitting device for lenshood according to this invention,

FIG. 2 is a cross-sectional view showing a state before the bayonetmount is effected in the embodiment shown in FIG. 1,

FIG. 3 is a cross-sectional view showing a state after the bayonet mountis effected in the same embodiment, and

FIG. 4 to FIG. 6 inclusive show another embodiment of this invention,wherein FIG. 4 is a perspective view corresponding to FIG. 1, FIG. 5 isa cross-sectional view corresponding to FIG. 2, and FIG. 6 is acrosssectional view corresponding to FIG. 3.

DESCRIPTION OF PREFERRED EMBODIMENTS:

In FIG. 1, 1 denotes a lens tube of a camera, on the periphery of itsfront end portion, there are provided with three joining projections 2extending outwardly. 3

denotes a cylindrical lens hood having brims 3a on its inner peripherynear its rear end, in which brims, there are provided with notchedportions 3b for receiving the joining projections 2 of the lens tube. 4denotes ajoining ring fitted in the inner periphery of said lens hood 3,having notched portions 4b for receiving the projections 2 of the lenstube and projecting brims 4a engageable with said projections 2, to befixed to said brims 3a of the hood 3 by means of small screws 5. 6a and6b denote holding pieces made of elastic material, which are pushed inthe notched portions provided on the peripheral wall of ring 4 incapablyof slipping out to the central direction and are caught and fixed amongthe peripheral wall 3c of lens hood 3, the brims 3a and 4a, and theircircular ends are slightly projecting from the inner peripheral surface4c of the ring 4.

7 denotes stoppers for the joining projections 2 and are provided at thecenter of the brims 4a, and said holding pieces 6a, 6b are symmetricallyarranged on both sides of the stoppers 7 near both ends of said brims4a.

As shown in FIG. 2, when the lens hood 3 is fitted on the front end ofthe lens tube I by setting the projections 2 to the notched portions 4band the lens hood is turned to the direction of the arrow at a positionwhere the rear end of the ring 4 abuts on the shoulder 1a of the lenstube 1, the projections 2 will enter in the gaps between the brims 3aand 4a, then the circular face of the holding pieces 6a will hit on theslanting surfaces of the projections 2 and by successive turning of thehood, the holding pieces 6a are compressed to get over the slantingsurfaces 2a of the projections 2, thus to contact with the outerperiphery 2b. The turning of lens hood is stopped at a position wherethe stoppers 7 hit on the slanting faces 2a of the projections 2, andthe movement of the hood in the direction of optical axis is obstructedby the engagement of the brims 4a with the joining projections 2 of thelens tube, as shown in FIG. 3, thus the resiliences of three holdingpieces 6a act between the outer periphery 2b of the projections 2 andthe peripheral wall 30 of the hood to obstruct said movement of thehood, which will be fixed to the lens tube then.

When the lens hood is turned from the position of FIG. 2 in oppositedirection of the arrow, the holding pieces 6b may act on the projections2 to fix the hood in the same manner as the case mentioned above.

In this embodiment, the lens hood is provided with the brims 3a and 4aof the same shape facing each other, the stoppers 7 are provided at thecenter of the projections and the holding pieces 6a and 6b are providedsymmetrically, so that there is an advantage that the lens hood may beturned either to the right or to the left, when it is fitted on the lenstube. Particularly, when a camera is received in a leather case and thelens hood is turned upside down to put on the lens tube, it may bejoined with bayonet by turning the hood in the same direction as thefitting for use, so that it is very convenient for use, since the usermay turn the hood to the same direction in either case according to hishabit.

FIG. 4 to FIG. 6 inclusive show another embodiment of this invention,wherein 4' denotes a fitting ring made of synthetic resin, 4'!) notchedportions for receiving the joining projections 2 of the lens tube, andon a part of projections 4'0, brims 4'a and 4a are provided face to faceputting a groove 4'e between them, and one end of this groove is formedas a stopper for the projections 2 of the lens tube. 6 denotes holdingpieces, of which front ends are slightly projecting from the innerperipheral surface of said groove 4'e through holes passing through theperipheral wall of said ring 4'.

The ring 4' is fixed by means of screws or rivets and the like on brims3' which are provided on the inner periphery near the rear end of a lenshood 3, in the same manner as the case of above mentioned embodiment.

As shown in FIG. 5, when the lens hood is fitted on the lens tube bysetting the projections 2 to the notched portions 4'b and is turned tothe direction of the arrow, the holding pieces 6 are compressed to moveon the outer periphery of the projections 2, thus the hood is stopped ata position where stoppers 4d hit on the projections 2, in the samemanner as above mentioned case. Hereupon, the interval between thestoppers 4'11 and the holding pieces 6 is little narrower than the widthof the projections 2, so that the holding pieces 6 will get over theouter periphery of projections 2 to fall in the slanting surface ofopposite side and contact with said surface by little pressure toobstruct the turning of the lens hood, as shown in FIG. 6.

In this embodiment, the fitting ring 4' is made of syn- I thetic resin,so that even though there are any friction between the joiningprojections 2 of the lens tube and the brims 4'a, the surface of theprojections 2 will never be injured and since little deformation of theholding pieces remains at the stop position, the holding pieces willcause little permanent deformation, even though they are left intact.

in view of the explanation about said embodiments, according to thisinvention, in a fitting device for the accessories such as lens hood,filter and the like, the holding pieces made of elastic material arecompressed between the accessories and the joining projections and theresiliency of said pieces is made to act in the radial direction of lensto hold the accessories on the lens tube, so that the device has such aneffect that the accessories may be simply and surely held on the lenstube without injuring the tube nor its external appearance.

As the material for said holding pieces, synthetic rubber, such asurethan-rubber, fluorine-rubber, siliconrubber, neoprene-rubber and thelike may be used, however, the material is by no means limited to thesekinds, but any other material may be used therefor, if it has propercompression-proof property and elasticity and never cause permanentdeformation by the compression for a long time.

We claim:

1. A fitting device for use in detachably securing a tubular accessoryhaving a securing end with an internal ring recessed in said securingend to a camera having a tubular camera portion with a plurality ofcircumferentially spaced mounting projections, comprising a joining ringadapted to be secured to the internal ring of the accessory and having aplurality of circumferentially spaced holding projections with the sizeof said tube being sufficient to receive the tubular camera portion withthe spacing between the holding projections being sufficient toaccommodate said mounting projections therebetween, said holdingprojections being spaced from the internal ring of the accessory tubewhen said joining ring is secured to said accessory tube,

said joining ring having a plurality of circumferentially spacedinwardly extending resilient holding portions which engage against themounting projections when the accessory tube with said joining ring arerotated after they are positioned over the tubular camera portion andthe mounting projections are inserted between the holding projectionsand thereafter to position the holding projections behind the mountingprojections and to compressively engage the holding projections with theresilient holding portions.

2. A fitting device, according to claim 1, wherein said accessory ringincludes an inwardly extending stopper centrally disposed over each ofsaid holding projections, said resilient holding portions being locatedon each side of said stopper which compressively engage with themounting projections when they are positioned behind said holdingprojections.

3. A fitting device, according to claim 1, wherein sa d tubularaccessory comprises a lens tube having said internal ring, said ringbeing spaced from said holding projections in an axial direction toaccommodate said mounting projections therebetween.

4. A fitting device, according to claim 1, wherein said accessory ringincludes holding projections in the form of two axially spacedprojections forming a notch therebetween for receiving the mountingprojections therein.

5. A fitting device, according to claim 1, wherein said resilientholding portions comprise a synthetic material.

6. A fitting device, according to claim 1, including means on saidaccessory ring for securing said ring to the ring of said tubularaccessory.

7. A fitting device, according to claim 1, wherein said resilientholding portions comprise inwardly extending rounded resilient members.

8. An accessory fitting device of the bayonet mount type for use with,in combination, a camera and an accessory for the camera, theconstruction comprising a lens tube of the camera having a front portionjoining with a plurality of joining projections and an accessory for thecamera having a tubular fitting portion for said lens tube, a pair ofopposed brim-like substantially similarly shaped projections mounted insaid fitting portion in spaced relationship to each other so as todefine a nip for receiving said joining projections therebetween, andwhich can be attached not only in the forward direction but in theinverse direction to the lens tube, said accessory being rotatablethrough a certain angle from the position at which it fits the lens tubeto one in which the brim-like projections engage behind the joiningprojections, said fitting device being engageable in said tubularfitting portion and engaged against said lens tube and having aplurality of inwardly projecting holding pieces made of elasticmaterial, compressed against the projections of said lens tube and theaccessory in the interlocked position so that the accessory can be heldon the lens tube by said holding pieces.

1. A fitting device for use in detachably securing a tubular accessory having a securing end with an internal ring recessed in said securing end to a camera having a tubular camera portion with a plurality of circumferentially spaced mounting projections, comprising a joining ring adapted to be secured to the internal ring of the accessory and having a plurality of circumferentially spaced holding projections with the size of said tube being sufficient to receive the tubular camera portion with the spacing between the holding projections being sufficient to accommodate said mounting projections therebetween, said holding projections being spaced from the internal ring of the accessory tube when said joining ring is secured to said accessory tube, said joining ring having a plurality of circumferentially spaced inwardly extending resilient holding portions which engage against the mounting projections when the accessory tube with said joining ring are rotated after they are positioned over the tubular camera portion and the mounting projections are inserted between the holding projections and thereafter to position the holding projections behind the mounting projections and to compressively engage the holding projections with the resilient holding portions.
 2. A fitting device, according to claim 1, wherein said accesSory ring includes an inwardly extending stopper centrally disposed over each of said holding projections, said resilient holding portions being located on each side of said stopper which compressively engage with the mounting projections when they are positioned behind said holding projections.
 3. A fitting device, according to claim 1, wherein said tubular accessory comprises a lens tube having said internal ring, said ring being spaced from said holding projections in an axial direction to accommodate said mounting projections therebetween.
 4. A fitting device, according to claim 1, wherein said accessory ring includes holding projections in the form of two axially spaced projections forming a notch therebetween for receiving the mounting projections therein.
 5. A fitting device, according to claim 1, wherein said resilient holding portions comprise a synthetic material.
 6. A fitting device, according to claim 1, including means on said accessory ring for securing said ring to the ring of said tubular accessory.
 7. A fitting device, according to claim 1, wherein said resilient holding portions comprise inwardly extending rounded resilient members.
 8. An accessory fitting device of the bayonet mount type for use with, in combination, a camera and an accessory for the camera, the construction comprising a lens tube of the camera having a front portion joining with a plurality of joining projections and an accessory for the camera having a tubular fitting portion for said lens tube, a pair of opposed brim-like substantially similarly shaped projections mounted in said fitting portion in spaced relationship to each other so as to define a nip for receiving said joining projections therebetween, and which can be attached not only in the forward direction but in the inverse direction to the lens tube, said accessory being rotatable through a certain angle from the position at which it fits the lens tube to one in which the brim-like projections engage behind the joining projections, said fitting device being engageable in said tubular fitting portion and engaged against said lens tube and having a plurality of inwardly projecting holding pieces made of elastic material, compressed against the projections of said lens tube and the accessory in the interlocked position so that the accessory can be held on the lens tube by said holding pieces. 